Holliday and the others were members of the Army’s 1st Squadron, 40th Cavalry Regiment, 4th Brigade Combat Team (Airborne), 25th Infantry Division, based in Fort Richardson, Alaska, according to defense officials.

The 21-year-old always wanted to be in the armed forces and began researching which branch he wanted to go into when he was 11, his mother, Kelly Holliday, said. He joined the Army in 2005, when he was 19.

“That was always his desire — to go into the military and serve,” Holliday said. “When 9/11 happened, he was 15, and he said, ‘If I were old enough to serve, I would.’ ”

The oldest of eight siblings — seven boys and one girl — Holliday was home-schooled and graduated through the Christian Home Education Fellowship of Oklahoma in 2004, his mother said. At his graduation, he played the piano and received a standing ovation, said his mother.

“He was a people-watcher,” she said. “He loved people. He was the kind of person who, if he saw someone sitting by themselves looking depressed or upset, he made it his mission to make them smile before he left, and usually accomplished that goal.”